The present invention is directed to a testing method for subscriber line testing in a program-controlled communications system.
A functionally reliable telecommunications port is an important prerequisite for a telecommunications subscriber to reliably use the services and performance features of a telecommunications network or telecommunications system. The hardware and software modules required for a subscriber line testing system integrated in a telecommunications system are respectively implemented therein. In detail, processor-controlled testing procedures such as, for example, quality analysis, error recognition, error diagnosis or error localizing in a subscriber circuit/subscriber circuit module or at a subscriber line with subscriber terminal equipment can be implemented with the electronic hardware and software modules integrated in the systems. Furthermore, the subscriber line testing system of the telecommunications system enables an automatic test execution initiated via a telecommunication port. The above-identified subscriber line tests integrated in the system are controlled by operating software of a processor. This processor is arranged on a line trunk group that is integrated between a switching network and a subscriber line unit of a telecommunications system.
A plurality of the greatest variety of testing procedures are initiated by events during a subscriber line testing integrated in the system, such as, for example: acceptance of commands from a coordination processor; transmitting messages to a coordination processor; connect test access onto a unit under test (for example subscriber circuit, subscriber line with subscriber terminal equipment); seize testing equipment, and implement test.
The program modules that initiate and execute testing procedures can be constituted differently, since the telecommunications systems or telecommunications networks can be adapted to different demands and can also be designed specifically for countries and individually oriented to subscribers. A plurality of differently constituted hardware modules are tested by the testing procedures. Due to the different nature of the hardware modules, testing program steps and decision criteria must be supplemented in the testing program modules or testing procedures must be adapted to the respective hardware modules.
Test limit values for classification of the measured test values are required according to the nature of the measurement, the nature of the subscriber line circuit and of the subscriber terminal equipment and are stored in test program modules customized for different countries. Among other things, subscriber line parameters such as, for example, capacity values, DC values and impedance values are taken into consideration in their specification. A nationally tailored fashioning of the test limit values is determined by the hardware modules employed in the telecommunications system and by the demands made of the telecommunications system by the respective telecommunications companies. The test limit values to be utilized in the program modules are dependent on a plurality of individual factors, for example: feed network of the subscriber circuit; exchange voltage; and, input impedance of the subscriber circuit, as well as the attenuation of the transmission/reception level. Furthermore, customer wishes must be taken into consideration in the realization and in the execution of the testing procedures as well as in the definition of the test limit values.
Testing procedures to be implemented can be divided into at least two test algorithms dependent on the nature of the "unit under test", for example a subscriber line circuit, a digital or analog subscriber line unit. A first test algorithm contains the testing of subscriber circuits and a second test algorithm contains the testing of the subscriber line with subscriber terminal equipment. During the execution of the test algorithms, an identified measured test value is respectively compared to an upper and to a lower test limit value in order to subsequently undertake a test quality classification (go/no go statement). Customer wishes with respect to modifications of an execution of a test algorithm after an implementation of the test program modules or of a matching of the test program modules to an individual line embodiment previously involved high work outlay.
A nationally customized adaptation of test limit value or a customer-associated adaptation of test limit values in a subscriber line circuit test required an involved software adaptation work in the respective test program modules. The software adaptation jobs, however, lead to a multitude of variant formations of a test program module and to a great documentation outlay in the test program modules produced in every instance. A variation of test limit values for an individual subscriber line test was previously not possible. Further, customer wishes with respect to an adaptation of test limit values could not be subsequently accepted in a subscriber line test. A test-oriented adaptation following a system modification or a modernization of the subscriber line test configured to be country-specific, required a great programming outlay. A classification of the measured test values proceeding beyond a "go" or "no go" statement was previously not possible, for example with respect to a quality statement about a "unit under test" in the subscriber line test. Errors in the test program executions respectively required an individual correction per patch.